This is a very common and annoying plumbing problem that can quickly cost you money. Luckily a running toilet is also easy to fix on your own. Toilets typically run when the flapper valve that lets water pass from the tank to the bowl no longer fits properly, the float is imbalanced or the fill tube comes loose. Toilet repair kits work for most models and require little effort to install. Occasionally, though, toilets run for more complex reasons. If you’ve replaced the flapper, float apparatus and fill tube, you may have sediment that’s affecting proper flushing and filling. Higher water bills could also indicate a silent leak. To detect a silent leak in your toilet, add a few drops of food coloring to the upper tank and wait 15 to 20 minutes. Look in the bowl for any hint of color; if you see tinted water, your flapper valve isn’t working as it should. If all else fails or you do feel confident in taking on such a task, then call a plumber to repair the toilet before it turns into a major loss.